This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Our goal is to develop magnetic resonance imaging based molecular imaging systems to image cancer-specific enzymatic activity of protease in vivo. The platform is based on the protease activity triggered polymerization between two chemical moieties (the amino and the thiol groups of cysteine and 2-cyanobenothiozole) incorporated into a small-molecule imaging probe. This polymerization process converts the small-molecule probe into larger molecules (or even nanoparticles) to achieve probe concentration and retention at the target site and to generate amplified readout signals. To read about other projects ongoing at the Lucas Center, please visit http://rsl.stanford.edu/ (Lucas Annual Report and ISMRM 2011 Abstracts)